1. Field of the Invention
The present invention relates generally to the field of light box displays of the type used to present advertising comprising a replaceable graphics sheet positioned in front of a diffused light source. The invention pertains more specifically to such a light box uniquely configured to provide access only from the front of the display such as for changing the graphics or performing maintenance on the light box.
2. Background Art
Light boxes of the type disclosed herein have been in widespread use for at least the past forty years. See for example issued U.S. Pat. Nos. 3,390,259 and 3,391,481, both issued in 1968. Typically, such light boxes provide a rectangular housing having a distributed light source such as a plurality of spaced fluorescent tubes and a diffusing transparent or translucent surface for spreading the light evenly across the housing where it exits from a rectangular opening. Some form of graphics are provided either printed directly on the diffusing surface or on a flexible graphics sheet which is placed immediately in front of the diffusing surface.
In recent years, such light box displays have become more common as advertising systems as opposed to signs. Typically, advertising light boxes are wall mounted inside retail stores or where there is a great deal of foot traffic such as in airports, train stations, indoor malls and the like. Advertising light box displays normally utilize changeable graphics so that their advertising content can be modified relatively often. Such graphics are usually provided as a unitary flexible plastic film vinyl, paper, fabric or other substrate which has the advertising indicia printed on it and which is inserted into the light box in contiguous relation to the diffusing surface in front of the lighting source. The current trend appears to be to make such advertising light box displays quite large, such as four to six feet in height and eight to sixteen feet in length. They're typically four to twelve inches in thickness or depth. Conventional light box displays are simply affixed to the exterior surface of a wall. However, given the considerable cost of retail space, there is a growing desire to install light box displays inside recesses of a wall so that they don't extend beyond the wall's exterior surface. Such installations however create problems relating to access to the light box interior which is necessary to change out graphics and to perform maintenance such as replacing burned out light bulbs. Such access is normally gained from the side or rear of the light box or from a removable front element. However, side or rear access usually complicates the structure of the light box making it more expensive to manufacture. More importantly, side or rear access may require either that the light box be capable of being removed from its recess (which has significant impact on aesthetics and maintenance costs) or that some structural modifications be made to the surrounding wall to allow personnel to gain such access (which increases construction cost and may require wasteful use of costly retail space). Moreover, some retailers may wish to provide flush mounted light box surfaces which are overlapped by adjacent wall surfaces for aesthetics, thereby making it virtually impossible to provide front, side or rear access to the light box display.
Not having side or rear access to a flush mounted light box display, means that one must have frontal access to change the graphics and perform maintenance tasks. However, with the sheet of graphics being as large as the light box frontal area and being mounted flush with the front surface of the light box, it is not immediately apparent how to gain frontal access to replace the graphics or perform maintenance tasks. This is the problem that is addressed by the present invention.